CA2670918A1 - Flight control system - Google Patents
Flight control system Download PDFInfo
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- CA2670918A1 CA2670918A1 CA002670918A CA2670918A CA2670918A1 CA 2670918 A1 CA2670918 A1 CA 2670918A1 CA 002670918 A CA002670918 A CA 002670918A CA 2670918 A CA2670918 A CA 2670918A CA 2670918 A1 CA2670918 A1 CA 2670918A1
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- Prior art keywords
- flight control
- control system
- flight
- drag
- aircraft
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- RZVHIXYEVGDQDX-UHFFFAOYSA-N 9,10-anthraquinone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3C(=O)C2=C1 RZVHIXYEVGDQDX-UHFFFAOYSA-N 0.000 title claims abstract description 57
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- 238000012545 processing Methods 0.000 claims description 21
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- 230000003416 augmentation Effects 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 4
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Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/04—Control of altitude or depth
- G05D1/06—Rate of change of altitude or depth
- G05D1/0607—Rate of change of altitude or depth specially adapted for aircraft
- G05D1/0653—Rate of change of altitude or depth specially adapted for aircraft during a phase of take-off or landing
- G05D1/0676—Rate of change of altitude or depth specially adapted for aircraft during a phase of take-off or landing specially adapted for landing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C19/00—Aircraft control not otherwise provided for
- B64C19/02—Conjoint controls
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C9/00—Adjustable control surfaces or members, e.g. rudders
- B64C9/32—Air braking surfaces
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/04—Control of altitude or depth
- G05D1/06—Rate of change of altitude or depth
- G05D1/0607—Rate of change of altitude or depth specially adapted for aircraft
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/08—Control of attitude, i.e. control of roll, pitch, or yaw
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
- G05D1/08—Control of attitude, i.e. control of roll, pitch, or yaw
- G05D1/0808—Control of attitude, i.e. control of roll, pitch, or yaw specially adapted for aircraft
Abstract
A flight control system commands drag devices such as flight spoilers acc ording to pilot or autopilot longitudinal command. Furthermore, the flight c ontrol system monitors a set of flight parameters (18 - 21) to determine whe ther the aircraft is operating inside the permitted safe envelope, hence, in corporating envelope automatic exceeding disengagement. This invention allow s the aircraft to descend in a steeper glide path than the 3° used in the no rmal approach, while keeping speeds unchanged.
Description
Flight Control System The present invention relates to a flight control system for an aircraft.
-5 Considering an aircraft, equipped with an engine, it is well lcnown that there exists a inaxiinum descent glide slope possible in a constant airspeed steady state flight. This will depend on the lift, drag and thrust produced by the aircraft in such a flight condition. The problem is that some operations require capability of performing a steady flight in a steeper descent path, although, i o depending on the conditions mentioned above, a given aircraft may lack this capability at a certain relatively low airspeed. In these cases, the most commonly used solution is to introduce devices, mechanisins and methods to produce more drag in the aircraft, in order perinit a steeper descent trajectory.
In the prior art, many proposed solutions utilise drag devices, e.g.
airbrakes, 15 flight spoilers, dive brakes and others.
An object of the present invention is to provide a flight control system which can achieve a relatively steep descent (using drag devices such as flight spoilers for example) at relatively low speeds.
It is well lcnown in aeronautics engineering that drag devices such as flight spoilers are capable of increasing the inaximum descent ratio. Consequently, prior art arrangements have used such devices in order to increase the angle of the glide path. Nevertheless, this sort of solution may have drawbacks because of undesirable collateral effects caused by using such devices, as follows:
i) For a given angle of attack, it is possible that drag devices such as spoilers reduce the lift produced by the aircraft, thus reducing significantly the margins to the stall condition. Consequently, there is a concern regarding the speed inargins that are required for a safe flight operation. It is possible that speed enhancements will be necessary in order to regain the same margins as before, jeopardizing the performance of aircraft approaches.
ii) It is desirable for the aircraft to carry the salne payload; thus the total lift lnust be maintained in the steep descent configuration, regardless
-5 Considering an aircraft, equipped with an engine, it is well lcnown that there exists a inaxiinum descent glide slope possible in a constant airspeed steady state flight. This will depend on the lift, drag and thrust produced by the aircraft in such a flight condition. The problem is that some operations require capability of performing a steady flight in a steeper descent path, although, i o depending on the conditions mentioned above, a given aircraft may lack this capability at a certain relatively low airspeed. In these cases, the most commonly used solution is to introduce devices, mechanisins and methods to produce more drag in the aircraft, in order perinit a steeper descent trajectory.
In the prior art, many proposed solutions utilise drag devices, e.g.
airbrakes, 15 flight spoilers, dive brakes and others.
An object of the present invention is to provide a flight control system which can achieve a relatively steep descent (using drag devices such as flight spoilers for example) at relatively low speeds.
It is well lcnown in aeronautics engineering that drag devices such as flight spoilers are capable of increasing the inaximum descent ratio. Consequently, prior art arrangements have used such devices in order to increase the angle of the glide path. Nevertheless, this sort of solution may have drawbacks because of undesirable collateral effects caused by using such devices, as follows:
i) For a given angle of attack, it is possible that drag devices such as spoilers reduce the lift produced by the aircraft, thus reducing significantly the margins to the stall condition. Consequently, there is a concern regarding the speed inargins that are required for a safe flight operation. It is possible that speed enhancements will be necessary in order to regain the same margins as before, jeopardizing the performance of aircraft approaches.
ii) It is desirable for the aircraft to carry the salne payload; thus the total lift lnust be maintained in the steep descent configuration, regardless
2 of the fact that drag devices such as spoilers might lcill soine lift. In these cases, other parts of the aircraft will be loaded more to coinpensate for this fiaction of killed lift, occasionally producing local overloading problerns.
iii) Deterioration of flying qualities, especially during steep approaches, flare and landing manoeuvres.
iv) Exposure to high touch down sink rate and tail strike, in steep approaches and landings.
In view of the above, some attempts have been inade in the prior art to incorporate some control of these surfaces, to reduce some of the effects mentioned above. The prior art includes the following:
US 3589648 by Gorhan and. Richter proposes a device in which the spoilers are biased to a predetennined position, and are coirunanded around this position depending on a signal received from an autopilot. The autopilot produces those signals based on a comparison between a reference trajectory, which is desirable; and the real trajectoiy sensed by aircraft systems. Hence, this patent discloses a command to the spoiler to correct the flight trajectory using a feedback signal, augmenting the aircraft response.
In US 3738594 to Donovan and Wood, a inechanisin is proposed in which spoilers are also biased to a predetermined position. Further, the aircraft pitch coinmand is connected to the spoilers through a "washout" or viscous dainping mechanism, in such a way that a quicker pitch command produces a higher ainplitude spoiler movement around the biased position, after which the inputs to the spoiler actuators are gradually returned to the original bias position.
US 3774869 to Hannon discloses a mechanism for connecting the throttle to the spoilers and dive bralces (this surface being located under the wing). In these cases, the inventors created a mechanism to coordinate the spoiler handle with thrust lever cominands, i.e., the drag produced by the spoiler auginents the thrust changes commanded by the pilot. Similar systems are presented in US 3850388 to Olcott et al., and US 4489907 to Ziegelmeyer.
iii) Deterioration of flying qualities, especially during steep approaches, flare and landing manoeuvres.
iv) Exposure to high touch down sink rate and tail strike, in steep approaches and landings.
In view of the above, some attempts have been inade in the prior art to incorporate some control of these surfaces, to reduce some of the effects mentioned above. The prior art includes the following:
US 3589648 by Gorhan and. Richter proposes a device in which the spoilers are biased to a predetennined position, and are coirunanded around this position depending on a signal received from an autopilot. The autopilot produces those signals based on a comparison between a reference trajectory, which is desirable; and the real trajectoiy sensed by aircraft systems. Hence, this patent discloses a command to the spoiler to correct the flight trajectory using a feedback signal, augmenting the aircraft response.
In US 3738594 to Donovan and Wood, a inechanisin is proposed in which spoilers are also biased to a predetermined position. Further, the aircraft pitch coinmand is connected to the spoilers through a "washout" or viscous dainping mechanism, in such a way that a quicker pitch command produces a higher ainplitude spoiler movement around the biased position, after which the inputs to the spoiler actuators are gradually returned to the original bias position.
US 3774869 to Hannon discloses a mechanism for connecting the throttle to the spoilers and dive bralces (this surface being located under the wing). In these cases, the inventors created a mechanism to coordinate the spoiler handle with thrust lever cominands, i.e., the drag produced by the spoiler auginents the thrust changes commanded by the pilot. Similar systems are presented in US 3850388 to Olcott et al., and US 4489907 to Ziegelmeyer.
3 In the arangement disclosed in WO 2006/016070A1, in the names of Boissenin and Rosay, spoilers are also deployed to a biased predetel-inined position. In this invention, the spoilers remain fixed in this position up to certain altitude, whence they are automatically and gradually cozninanded to a more faired position. Further, in this invention, hyper lifting devices are coirunanded in coordination with spoiler closure. There is no spoiler modulation based on pilot longitudinal coirunands.
io In all of the above disclosures, soine control is incorporated to attain an improvement of flying qualities.
In one aspect the invention provides a flight control system for an aircraft having a drrag device for increasing the angle of the descent path, the flight control system coinprising processing means for monitoring a plurality of flight parameters associated with a safe operating envelope of the aircraft, and control means coupled to the drag device and arranged to keep the aircraft within the safe operating envelope by reducing the drag of the drag device in response to an output of the processing ineans.
By inonitoring the flight paraineters and autoinatically closing the drag devices if the operative envelope of the function is exceeded, it is ensured that the stall and structure limit margins as found in the configuration with the drag devices faired are maintained, without any requirement for a physical modification of the airframe.
In another aspect the invention provides a flight control system for an aircraft, the flight control system coinprising processing lneans for monitoring a.
plurality of flight paraineters, wherein said processing means is aiTanged to generate a Boolean function of a plurality of logical inputs associated with the respective flight parameters and to generate an output signal, the flight control system being arranged to control at least one longitudinal flight control surface in response to said output signal and to a pilot or autopilot longitudinal coininand signal.
io In all of the above disclosures, soine control is incorporated to attain an improvement of flying qualities.
In one aspect the invention provides a flight control system for an aircraft having a drrag device for increasing the angle of the descent path, the flight control system coinprising processing means for monitoring a plurality of flight parameters associated with a safe operating envelope of the aircraft, and control means coupled to the drag device and arranged to keep the aircraft within the safe operating envelope by reducing the drag of the drag device in response to an output of the processing ineans.
By inonitoring the flight paraineters and autoinatically closing the drag devices if the operative envelope of the function is exceeded, it is ensured that the stall and structure limit margins as found in the configuration with the drag devices faired are maintained, without any requirement for a physical modification of the airframe.
In another aspect the invention provides a flight control system for an aircraft, the flight control system coinprising processing lneans for monitoring a.
plurality of flight paraineters, wherein said processing means is aiTanged to generate a Boolean function of a plurality of logical inputs associated with the respective flight parameters and to generate an output signal, the flight control system being arranged to control at least one longitudinal flight control surface in response to said output signal and to a pilot or autopilot longitudinal coininand signal.
4 PCT/BR2007/000340 In a prefelTed embodiment the above flight control system conunands drag devices such as a set of flight spoiler pairs, keeping or enhancing the flying qualities and manoeuvreability by modulating the drag devices as a function of longitudinal control, further providing an innovative protection to keep the saine margins and structural loading as found in a conventional flight control system.
In this new system, as found in the prior art, the spoilers arepreferably biased to a predetermined position, although a new coirnnand inechanisin is provided.
i o The position of the spoilers is preferably coinputed as a function of longitudinal pilot (or autopilot) command.
In a preferred embodiinent the system provides a spoiler cominand which creates extra drag as required in steep descents, approaches and landings.
Beyond creating extra drag, the flight control system preferably provides a spoiler augmentation command to enhance the longitudinal control of the aircraft, which is a modulation based on a pilot longitudinal command, used in conjunction with the elevators command.
2o The system preferably includes a logic module that receives a set of signals, and its task is to decide when the systeln is engaged, and thus, when the spoilers are deployed. The logic module optionally also receives a signal fioin a cockpit switch used to allow the pilot to override (i.e. engage or disengage) the system.
The function of the set of signals received by logic module is preferably twofold:
i) to identify the state of the flight; and '0 ii) to check the aircraft configuration, and decide if the system is operating within its operational envelope.
In response to the above, an autoinatic envelope exceeding disengageinent may be triggered. This feature provides structural protection, stall protection, and reduces the pilot worldoad when changing the aircraft configuration.
In this new system, as found in the prior art, the spoilers arepreferably biased to a predetermined position, although a new coirnnand inechanisin is provided.
i o The position of the spoilers is preferably coinputed as a function of longitudinal pilot (or autopilot) command.
In a preferred embodiinent the system provides a spoiler cominand which creates extra drag as required in steep descents, approaches and landings.
Beyond creating extra drag, the flight control system preferably provides a spoiler augmentation command to enhance the longitudinal control of the aircraft, which is a modulation based on a pilot longitudinal command, used in conjunction with the elevators command.
2o The system preferably includes a logic module that receives a set of signals, and its task is to decide when the systeln is engaged, and thus, when the spoilers are deployed. The logic module optionally also receives a signal fioin a cockpit switch used to allow the pilot to override (i.e. engage or disengage) the system.
The function of the set of signals received by logic module is preferably twofold:
i) to identify the state of the flight; and '0 ii) to check the aircraft configuration, and decide if the system is operating within its operational envelope.
In response to the above, an autoinatic envelope exceeding disengageinent may be triggered. This feature provides structural protection, stall protection, and reduces the pilot worldoad when changing the aircraft configuration.
5 Furthermore, in preferred einbodiments the longitudinal control surface sensitivities to their coinmand signals are -modified to - give better flying qualities when flying with the new system engaged. When engaging or disengaging the function. i.e., the spoilers coininanded to the biased position, an automatic longitudinal coininand is sent to elevators or to horizontal i o stabilizer in order to provide an automatic balancing of longitudinal moments due to spoiler pitch moment.
The invention also extends to an aircraft including the above-defined flight control systems.
Further preferred features are defined in the dependent claims.
A preferred einbodiinent of the invention is described below by way of exainple only with reference to Figures 1 to 6 of the accoznpanying drawings, wherein:
Figure 1 is a schematic plan view of one aircraft - a civil transporter turbo-fan;
Figure 2 is a schematic block diagra.in of the preferred. einbodinlent of the flight control system of the present invention, showing the basic architecture of the system;
Figure 3 is a schematic diagram of the function of the software of the above flight control system, showing how the pilot coinmand is transforined to a spoiler command under the control of a logic inodule;
Figure 4 is a diagram showing the details of the logic module, which enables the spoiler cominand based on a series of sensor inputs;
The invention also extends to an aircraft including the above-defined flight control systems.
Further preferred features are defined in the dependent claims.
A preferred einbodiinent of the invention is described below by way of exainple only with reference to Figures 1 to 6 of the accoznpanying drawings, wherein:
Figure 1 is a schematic plan view of one aircraft - a civil transporter turbo-fan;
Figure 2 is a schematic block diagra.in of the preferred. einbodinlent of the flight control system of the present invention, showing the basic architecture of the system;
Figure 3 is a schematic diagram of the function of the software of the above flight control system, showing how the pilot coinmand is transforined to a spoiler command under the control of a logic inodule;
Figure 4 is a diagram showing the details of the logic module, which enables the spoiler cominand based on a series of sensor inputs;
6 Figure 5 is a diagrairunatic illustration of the longitudinal control corninand of the system, and Figure 6 is a diagraininatic illustration of the longitudinal trim coinmand of the system.
The preferred einbodiinent of the invention is a system used in an aircraft equipped with longitudinal control, and a drag device, such as. spoilers, dive brakes, airbrakes, etc. Figure 1 shows an example: a twin turbo-fan engined io civilian transporter aircraft, with a wing (13) equipped with flight spoilers (12) installed in its upper surface.
Referring to Figure 2, the aircraft is equipped with a pilot switch 1 used to allow the pilot to cominand the engagement or disengageinent of the present system. The terin pilot switch encompasses a plurality of devices used in the aeronautic industry to perrnit the pilot to turn ON or OFF a system, comprising push buttons, levers, rotating buttons, and others. This flight control system receives the input position signals from the pilot longitudinal controller 2 command (p), and fioin pilot throttle lever 3(ST). The term pilot controller encompasses a plurality of devices used in aeronautics industry to allow the interface with the huinan pilot, e.g. coluinns, inini-columns, sticks, side-sticks and all others. The term pilot throttle lever encoinpasses a plurality of devices used in aeronautics to permit pilot interaction with the aircraft engine plant, which-produces the thrust.
Further, the system receives signals fioin a set of sensors, nainely: angle of attack 18 (S), airspeed 19 (u), the flap position 20 (Sr), gear position 21 (SG) and the in on-ground/in-air status 22 (bA1R).
'o The information flows via a parallel data bus 5. All these data, i.e. pilot commands, and sensor outputs, are sent to a prograinmable microprocessor (4). Then, inicroprocessor 4 is able to coinpute a spoiler colninand 6 based on the input data received. This coinmand is sent to a means for actuating a flight control surface 7, which coinprises a control unit able to coininand the spoiler surfaces to the coiTnnanded position. Consequently, the spoiler surfaces are deployed according to the coinlnand coinputed by inicrorocessor 4.
The preferred einbodiinent of the invention is a system used in an aircraft equipped with longitudinal control, and a drag device, such as. spoilers, dive brakes, airbrakes, etc. Figure 1 shows an example: a twin turbo-fan engined io civilian transporter aircraft, with a wing (13) equipped with flight spoilers (12) installed in its upper surface.
Referring to Figure 2, the aircraft is equipped with a pilot switch 1 used to allow the pilot to cominand the engagement or disengageinent of the present system. The terin pilot switch encompasses a plurality of devices used in the aeronautic industry to perrnit the pilot to turn ON or OFF a system, comprising push buttons, levers, rotating buttons, and others. This flight control system receives the input position signals from the pilot longitudinal controller 2 command (p), and fioin pilot throttle lever 3(ST). The term pilot controller encompasses a plurality of devices used in aeronautics industry to allow the interface with the huinan pilot, e.g. coluinns, inini-columns, sticks, side-sticks and all others. The term pilot throttle lever encoinpasses a plurality of devices used in aeronautics to permit pilot interaction with the aircraft engine plant, which-produces the thrust.
Further, the system receives signals fioin a set of sensors, nainely: angle of attack 18 (S), airspeed 19 (u), the flap position 20 (Sr), gear position 21 (SG) and the in on-ground/in-air status 22 (bA1R).
'o The information flows via a parallel data bus 5. All these data, i.e. pilot commands, and sensor outputs, are sent to a prograinmable microprocessor (4). Then, inicroprocessor 4 is able to coinpute a spoiler colninand 6 based on the input data received. This coinmand is sent to a means for actuating a flight control surface 7, which coinprises a control unit able to coininand the spoiler surfaces to the coiTnnanded position. Consequently, the spoiler surfaces are deployed according to the coinlnand coinputed by inicrorocessor 4.
7 Figure 3 details the prograin coded in microprocessor 4, presenting a signal flow schematic. This way, the system coinprises a controller to spoiler function 8, a logic module 9 and a logical signal switch 10.
The logic inodule 9 receives a set of signals that defines its operational envelope and state of flight, which comprise: the angle of attack 18 (5), airspeed 19 (u), pilot throttle lever position 23 (ST), the hyper-lifting devices (e.g. flap and/or slats) position 20 (8r), landing gear position 21 (6G) and on-to ground/in-air status 22 (bAIR). These variables, as well as the engagement pilot switch signal 24 (S) are all used in the logic rnodule which calculates a Boolean signal function engaged status 25 (bf), which is TRUE if the system is engaged and operating, or FALSE if it is not engaged.
The airspeed in aviation is a parameter coinputed based on airdata sensors, such as iinpact pressure or dynamic pressure. The speed is computed based on those data, or equivalently those raw parameters may be used directly instead of airspeed. Additionally, the logic module 9 may be responsive to a stall warning signal indicative of the stall warning system margin being exceeded.
2o The stall warning system margin may be as defined in FAR/JAR 25.207 "Stall Warning" for example.
The logic inodule 9 is detailed in the schematic of Figure 4. The logic module comprises the following logical interlocks: the angle of attack (S) shall be lower than a maximum angle perinitted (BLtM) (26), the airspeed shall be lower than UMAX speed (27) and greater than uMrN speed liinits (28), and the aircraft shall be in air (bAIR is TRLTE) (33).
Further, the logic module comprises interlocks 29, 3.1 and 32 to identify the 3o aircraft configuration, using respectively the parameters of pilot throttle angle (dT), hyper-lifting devices (flap andlor slat) position (Sj-.) and the gear position (SG). Basically, the logic inodule 9 coinpares the current aircraft configuration with that permitted to the system to be operative, and defined a priori.
Thus if all the above interlocks are TRUE then the aircraft is safely within the flight control system envelope..
The logic inodule 9 receives a set of signals that defines its operational envelope and state of flight, which comprise: the angle of attack 18 (5), airspeed 19 (u), pilot throttle lever position 23 (ST), the hyper-lifting devices (e.g. flap and/or slats) position 20 (8r), landing gear position 21 (6G) and on-to ground/in-air status 22 (bAIR). These variables, as well as the engagement pilot switch signal 24 (S) are all used in the logic rnodule which calculates a Boolean signal function engaged status 25 (bf), which is TRUE if the system is engaged and operating, or FALSE if it is not engaged.
The airspeed in aviation is a parameter coinputed based on airdata sensors, such as iinpact pressure or dynamic pressure. The speed is computed based on those data, or equivalently those raw parameters may be used directly instead of airspeed. Additionally, the logic module 9 may be responsive to a stall warning signal indicative of the stall warning system margin being exceeded.
2o The stall warning system margin may be as defined in FAR/JAR 25.207 "Stall Warning" for example.
The logic inodule 9 is detailed in the schematic of Figure 4. The logic module comprises the following logical interlocks: the angle of attack (S) shall be lower than a maximum angle perinitted (BLtM) (26), the airspeed shall be lower than UMAX speed (27) and greater than uMrN speed liinits (28), and the aircraft shall be in air (bAIR is TRLTE) (33).
Further, the logic module comprises interlocks 29, 3.1 and 32 to identify the 3o aircraft configuration, using respectively the parameters of pilot throttle angle (dT), hyper-lifting devices (flap andlor slat) position (Sj-.) and the gear position (SG). Basically, the logic inodule 9 coinpares the current aircraft configuration with that permitted to the system to be operative, and defined a priori.
Thus if all the above interlocks are TRUE then the aircraft is safely within the flight control system envelope..
8 The switch signal (S) toggles the state of the Boolean signal function engaged status (bf) according to the logic function 30: i) if bf is FALSE, and the paraineter S indicates that the switch is pressed, and if all other interlocks are TRUE, bf toggles to TRUE, ii) if bf is TRUE and the parameter S indicates that the switch is pressed, bf toggles to FALSE. Even if tlie switch status S
is TRUE, the logic shown in Figure 4 prevents flying outside the flight control system envelope.
io The logic switch 10 in Figure 3 is used to select whether the conunand auginentation to spoiler is enabled: if the system is engaged (bf= TRUE), the spoiler augmentation command from 8 is activated, otherwise, if disengaged (b f= FALSE), the spoiler augmentation cominarid is deactivated. Hence, when engaged (b f= TRUE), the pilot or autopilot longitudinal command is linked to is the spoilers through the function f(p) in 8, i.e., the spoiler will deploy fill in S s- f(p), augmenting the aircraft longitudinal control.
In this way, the system commands a set of spoilers (which may comprise any nuinber of flight spoiler pairs (or other drag devices)) selected a priori to be 2o enabled to perform the required function. Therefore the system shown in the Figure 2 can cominand any and all suitable spoilers.
This embodiment thus provides a spoiler command modulated by the longitudinal coiTunand of aircraft, via a spoiler auginentation conunand.
The prefeired embodiinent of the flight control system changes the "gearing"
ie the input:output slope of the control function of the pilot longitudinal controller to the longitudinal flight control surface; for instance, the elevator (15). A new gearing function 35 is used instead of another 34 used in the clean configuration without the drag device. The command is switched by a logic switch 36, which is activated by the function engaged status (bf) (25).
Referring to Figure 6, the flight control system includes an autoinatic longitudinal trim coininand offset to the pitch trim device. When the system engaged status bf = TRUE, an automatic pitch trim offset 37 is sent via a pitch trim coininand, to reduce the pilot workload during the function engagement.
is TRUE, the logic shown in Figure 4 prevents flying outside the flight control system envelope.
io The logic switch 10 in Figure 3 is used to select whether the conunand auginentation to spoiler is enabled: if the system is engaged (bf= TRUE), the spoiler augmentation command from 8 is activated, otherwise, if disengaged (b f= FALSE), the spoiler augmentation cominarid is deactivated. Hence, when engaged (b f= TRUE), the pilot or autopilot longitudinal command is linked to is the spoilers through the function f(p) in 8, i.e., the spoiler will deploy fill in S s- f(p), augmenting the aircraft longitudinal control.
In this way, the system commands a set of spoilers (which may comprise any nuinber of flight spoiler pairs (or other drag devices)) selected a priori to be 2o enabled to perform the required function. Therefore the system shown in the Figure 2 can cominand any and all suitable spoilers.
This embodiment thus provides a spoiler command modulated by the longitudinal coiTunand of aircraft, via a spoiler auginentation conunand.
The prefeired embodiinent of the flight control system changes the "gearing"
ie the input:output slope of the control function of the pilot longitudinal controller to the longitudinal flight control surface; for instance, the elevator (15). A new gearing function 35 is used instead of another 34 used in the clean configuration without the drag device. The command is switched by a logic switch 36, which is activated by the function engaged status (bf) (25).
Referring to Figure 6, the flight control system includes an autoinatic longitudinal trim coininand offset to the pitch trim device. When the system engaged status bf = TRUE, an automatic pitch trim offset 37 is sent via a pitch trim coininand, to reduce the pilot workload during the function engagement.
9 When disengaging, an opposite direction trim occurs because of the offset is removed.
The tenn pitch trim device refers to the devices responsible to balance the longitudinal lnoments and neutralizing the pilot/autopilot longitudinal command/force. The most coiTunon pitch trim devices are canards, trim tabs and horizontal stabilizer. For instance, in the twin-engine transporter of Figure 1, the pitch trim device is perforined by a movable horizontal stabilizer surface 17.
The logical switches 10, 36 and 38 have a fading in tinze and a fading out tiine, and the output signal is the result of an interpolation of both input signals during the fading tiine, such that the transition between the states of the function engaged does not cause any discontinuous transient.
Considering a flight control surface coininand, the term augmentation collunand is used in aviation to refer to an additive signal sulnined with all other pre-existing coinmands, such that, other cominands may be added to this auginentation comznand perforining other desirable functions. For instance, the spoilers may perform other functions as roll spoilers, speed bralce, ground spoilers and others.
The tenn pitch trim device refers to the devices responsible to balance the longitudinal lnoments and neutralizing the pilot/autopilot longitudinal command/force. The most coiTunon pitch trim devices are canards, trim tabs and horizontal stabilizer. For instance, in the twin-engine transporter of Figure 1, the pitch trim device is perforined by a movable horizontal stabilizer surface 17.
The logical switches 10, 36 and 38 have a fading in tinze and a fading out tiine, and the output signal is the result of an interpolation of both input signals during the fading tiine, such that the transition between the states of the function engaged does not cause any discontinuous transient.
Considering a flight control surface coininand, the term augmentation collunand is used in aviation to refer to an additive signal sulnined with all other pre-existing coinmands, such that, other cominands may be added to this auginentation comznand perforining other desirable functions. For instance, the spoilers may perform other functions as roll spoilers, speed bralce, ground spoilers and others.
Claims (24)
1. A flight control system for an aircraft having a drag device for increasing the angle of the descent path, the flight control system comprising processing means for monitoring, a plurality of flight parameters associated with a safe operating envelope of the aircraft, and control means coupled to the drag device and arranged to keep the aircraft within the safe operating envelope by reducing the drag of the drag device in response to an output of the processing means.
2. A flight control system according to 1 claim wherein said processing means is arranged to generate a Boolean function of a plurality of logical inputs associated with the respective flight parameters.
3. A flight control system according to claim 1 or claim 2 which is arranged in use to deploy one or more drag devices to a bias position and to vary the orientation thereof about the the bias positon in accordance with a spoiler augmentation signal which is a function of a longitudinal pilot or autopilot command signal and of said output of the processing means.
4. A flight control system according to claim 3 wherein said output of the processing means is a gating signal arranged to gate said spoiler augmentation signal.
5. A flight control system according to any preceding claim which is arranged in use to deploy one or more drag devices to a bias position only if the aircraft is inside the safe operating envelope.
6. A flight control system according to claim 5 which is arranged in use to respond to an input from a pilot switch which prevents deployment of said one or more drag devices to said bias position.
7. A flight control system according to any preceding claim wherein at least one longitudinal flight control surface is controlled by a pilot or autopilot command signal in accordance with a predetermined function of said command signal, said function being modified in accordance with said output of the processing means.
8. A flight control system according to claim 7 wherein said said output of the processing means is a selection signal arranged to select one of a plurality of such predetermined functions.
9. A flight control system according to claim 7 or claim 8 wherein said longitudinal flight control surface is an elevator.
10. A flight control system according to any preceding claim wherein at least one pitch trim device is controlled by said output of said processing means.
11. A flight control system according to any preceding claim wherein one of said flight parameters is a pilot or autopilot thrust command signal and said output of the processing means to reduce the drag of the drag device is generated in response to the commanded thrust being below a reference value.
12. A flight control system according to any preceding claim wherein one of said flight parameters is angle of attack of the aircraft and said output of the processing means to reduce the drag of the drag device is generated in response to the angle of attack being above a reference value.
13. A flight control system according to any preceding claim wherein one of said flight parameters is airspeed of the aircraft and said output of the processing means to reduce the drag of the drag device is generated in response to the airspeed being below a reference minimum value.
14. A flight control system according to any preceding claim wherein one of said flight parameters is airspeed of the aircraft and said output of the processing means to reduce the drag of the drag device is generated in response to the airspeed being above a reference maximum value.
15. A flight control system according to any preceding claim wherein one of said flight parameters is on ground/in air status and said output of the processing means to reduce the drag of the drag device is generated in response to the aircraft being on ground.
16. A flight control system according to any preceding claim wherein one of said flight parameters is hyper-lifting device deployment status and said output of the processing means to reduce the drag of the drag device is generated in response to a hyper-lifting device being deployed or deployed beyond a reference state.
17. A flight control system according to any preceding claim wherein one of said flight parameters is a stall warning system margin and said output of the processing means to reduce the drag of the drag device is generated in response to the aircraft exceeding the stall warning system margin.
18. A flight control system according to any preceding claim wherein one of said flight parameters is the deployment status of the aircraft landing gear.
19. A flight control system for an aircraft, the flight control system comprising processing means for monitoring a plurality of flight parameters, wherein said processing means is arranged to generate a Boolean function of a plurality of logical inputs associated with the respective flight parameters and to generate an output signal, the flight control system being arranged to control at least one longitudinal flight control surface in response to said output signal and to a pilot or autopilot longitudinal command signal.
20. A flight control system according to claim 19 wherein said at least one longitudinal flight control surface is controlled by a pilot or autopilot command signal in accordance with a predetermined function of said command signal, said function being modified in accordance with said output signal.
21. A flight control system according to claim 20 wherein said said output signal is a selection signal arranged to select one of a plurality of such predetermined functions.
22. A flight control system according to any of claims 19 to 21 wherein said longitudinal flight control surface is an elevator.
23. A flight control system substantially as described hereinabove with reference to Figures 1 to 4, optionally as modified in accordance with Figure or Figure 6 of the accompanying drawings.
24. An aircraft including a flight control system as claimed in any preceding claim.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0624700.1 | 2006-12-11 | ||
| GB0624700A GB2444742B (en) | 2006-12-11 | 2006-12-11 | Flight Control System |
| PCT/BR2007/000340 WO2008070944A2 (en) | 2006-12-11 | 2007-12-11 | Flight control system |
Publications (2)
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| CA2670918A1 true CA2670918A1 (en) | 2008-06-19 |
| CA2670918C CA2670918C (en) | 2016-05-03 |
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| CA2670918A Active CA2670918C (en) | 2006-12-11 | 2007-12-11 | Flight control system |
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| US (1) | US9405295B2 (en) |
| EP (1) | EP2104886B1 (en) |
| BR (1) | BRPI0709485B1 (en) |
| CA (1) | CA2670918C (en) |
| GB (1) | GB2444742B (en) |
| WO (1) | WO2008070944A2 (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2942612B1 (en) * | 2009-03-02 | 2012-09-28 | Airbus France | METHOD AND DEVICE FOR AUTOMATIC OPTIMIZATION ON THE GROUND OF THE AERODYNAMIC CONFIGURATION OF AN AIRCRAFT |
| RU2443602C2 (en) * | 2009-11-26 | 2012-02-27 | Московский государственный университет приборостроения и информатики | Aircraft pitch automatic control system |
| FR2956512B1 (en) * | 2010-02-16 | 2012-03-09 | Airbus Operations Sas | METHOD AND DEVICE FOR AUTOMATIC PROTECTION OF AN AIRCRAFT AGAINST AN EXCESSIVE DESCENT RATE. |
| US8666567B2 (en) | 2011-03-31 | 2014-03-04 | Honeywell International Inc. | Systems and methods for controlling the speed of an aircraft |
| FR2980610B1 (en) * | 2011-09-23 | 2014-07-11 | Airbus Operations Sas | METHOD AND DEVICE FOR PREDICTING FUEL CONSUMPTION ON AN AIRCRAFT. |
| US8606437B2 (en) * | 2011-11-28 | 2013-12-10 | Embraer S.A. | Flight control system mode and method providing aircraft speed control through the usage of momentary on-off control |
| US8781653B2 (en) * | 2012-01-11 | 2014-07-15 | The Boeing Company | Quiet landing attitude modifier for airplane |
| US9153139B2 (en) * | 2012-12-21 | 2015-10-06 | Embraer S.A. | Steep approach performance improvements and optimization |
| JP6097596B2 (en) * | 2013-02-28 | 2017-03-15 | 三菱航空機株式会社 | Grand spoiler drive system and aircraft |
| FR3010696B1 (en) * | 2013-09-13 | 2015-10-09 | Airbus Operations Sas | METHOD AND SYSTEM FOR CONTROLLING FLIGHT OF AN AIRCRAFT |
| US20150321748A1 (en) * | 2014-05-08 | 2015-11-12 | Honeywell International Inc. | Speed brake alerting system and method |
| CN105094141A (en) * | 2014-05-20 | 2015-11-25 | 哈尔滨飞机工业集团有限责任公司 | Digital autopilot system of lightweight fixed-wing aircraft |
| US9821903B2 (en) * | 2014-07-14 | 2017-11-21 | The Boeing Company | Closed loop control of aircraft control surfaces |
| CN105955288B (en) * | 2016-07-15 | 2021-04-09 | 北京远度互联科技有限公司 | Aircraft positioning and control method and system |
| US10228692B2 (en) | 2017-03-27 | 2019-03-12 | Gulfstream Aerospace Corporation | Aircraft flight envelope protection and recovery autopilot |
| CN110162064A (en) * | 2019-06-14 | 2019-08-23 | 湖南汽车工程职业学院 | A kind of automatic Pilot positioning and control system for tour bus |
| US11679865B2 (en) | 2021-06-21 | 2023-06-20 | Honeywell International Inc. | Aircraft yoke interference detection system and method |
Family Cites Families (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3040316A (en) * | 1959-06-22 | 1962-06-19 | Delaine C Sather | Limiting circuit for an aircraft control system |
| US3252675A (en) * | 1963-10-18 | 1966-05-24 | Sperry Rand Corp | Monitoring apparatus for aircraft control system |
| US3589648A (en) * | 1969-01-02 | 1971-06-29 | Lockheed Aircraft Corp | Means for controlling the vertical path of an aircraft |
| US3870253A (en) * | 1971-07-21 | 1975-03-11 | Mc Donnell Douglas Corp | Aircraft vectored flight control means |
| US3738594A (en) | 1971-08-16 | 1973-06-12 | Mc Donnell Douglas Corp | Lift control mechanism |
| US3774869A (en) | 1972-03-07 | 1973-11-27 | K Harmon | Combined throttle spoiler actuator for aircraft |
| US3850388A (en) | 1972-03-23 | 1974-11-26 | Nasa | Integrated lift/drag controller for aircraft |
| US4106730A (en) * | 1976-10-01 | 1978-08-15 | The Boeing Company | Engine out control system for STOL aircraft |
| US4266743A (en) * | 1979-02-28 | 1981-05-12 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Pitch attitude stabilization system utilizing engine pressure ratio feedback signals |
| US4261537A (en) * | 1979-02-28 | 1981-04-14 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Velocity vector control system augmented with direct lift control |
| US4363098A (en) * | 1980-06-24 | 1982-12-07 | The Boeing Company | Electric command spoiler system |
| US4489907A (en) | 1982-06-23 | 1984-12-25 | Precise Flight, Inc. | Selectively integrated throttle spoiler actuator for aircraft |
| US4849900A (en) * | 1986-05-02 | 1989-07-18 | The Boeing Company | Flight control system and method |
| FR2661149B1 (en) * | 1990-04-24 | 1992-08-14 | Aerospatiale | SYSTEM FOR THE PILOTAGE OF AN AIRPLANE IN TANGAGE. |
| US5337982A (en) * | 1991-10-10 | 1994-08-16 | Honeywell Inc. | Apparatus and method for controlling the vertical profile of an aircraft |
| FR2719548B1 (en) * | 1994-05-03 | 1996-07-05 | Aerospatiale | Transport plane with front tail. |
| US5826834A (en) * | 1994-10-19 | 1998-10-27 | Honeywell Inc. | Self adaptive limiter for automatic control of approach and landing |
| US5823479A (en) * | 1996-05-20 | 1998-10-20 | The Boeing Company | Landing attitude modifier for airplane |
| US6062513A (en) * | 1998-09-14 | 2000-05-16 | The Boeing Company | Total energy based flight control system |
| US6246929B1 (en) * | 1999-06-16 | 2001-06-12 | Lockheed Martin Corporation | Enhanced stall and recovery control system |
| DE10160315A1 (en) * | 2001-12-07 | 2003-11-13 | Airbus Gmbh | Device for the approach control of an aircraft |
| US6885917B2 (en) * | 2002-11-07 | 2005-04-26 | The Boeing Company | Enhanced flight control systems and methods for a jet powered tri-mode aircraft |
| FR2859174B1 (en) * | 2003-08-26 | 2006-03-10 | Airbus France | METHOD AND DEVICE FOR CONTROLLING THE PLATE OF AN AIRCRAFT |
| JP5184884B2 (en) * | 2004-07-16 | 2013-04-17 | エアバス オペラシオン ソシエテ パ アクシオンス シンプリフィエ | Method and apparatus for improving aircraft maneuverability during the pre-landing approach phase and subsequent nose |
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2006
- 2006-12-11 GB GB0624700A patent/GB2444742B/en active Active
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2007
- 2007-12-11 WO PCT/BR2007/000340 patent/WO2008070944A2/en active Application Filing
- 2007-12-11 CA CA2670918A patent/CA2670918C/en active Active
- 2007-12-11 BR BRPI0709485A patent/BRPI0709485B1/en active IP Right Grant
- 2007-12-11 US US12/518,361 patent/US9405295B2/en active Active
- 2007-12-11 EP EP07845466.7A patent/EP2104886B1/en active Active
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| Publication number | Publication date |
|---|---|
| CA2670918C (en) | 2016-05-03 |
| WO2008070944A2 (en) | 2008-06-19 |
| BRPI0709485B1 (en) | 2019-01-29 |
| BRPI0709485A2 (en) | 2011-07-19 |
| US20100217460A1 (en) | 2010-08-26 |
| GB0624700D0 (en) | 2007-01-17 |
| US9405295B2 (en) | 2016-08-02 |
| EP2104886A2 (en) | 2009-09-30 |
| EP2104886A4 (en) | 2013-07-24 |
| EP2104886B1 (en) | 2017-11-22 |
| GB2444742A (en) | 2008-06-18 |
| GB2444742B (en) | 2011-06-08 |
| BRPI0709485A8 (en) | 2018-05-02 |
| WO2008070944A3 (en) | 2009-04-02 |
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